start_interactive_sign_in

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description must fully disclose behavioral traits. It only states that the tool starts the flow and returns instructions, but it fails to mention side effects (e.g., expiration of the code), required prior auth state, or whether the call blocks until completion. This is a significant gap for a tool initiating an authentication flow.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, front-loaded sentence that immediately conveys the action and output. There is no wasted text, and it is appropriately sized for a tool with no parameters.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Although an output schema exists, the description does not provide needed context about the overall sign-in flow. It omits prerequisites (e.g., session authentication), typical usage sequence, or what the instructions look like. Given the tool is part of a multi-step authentication process, the minimal description leaves the agent without enough context to invoke it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema has zero parameters, so there is nothing to explain. The description correctly avoids adding parameter details, and the baseline of 4 applies because the tool requires no arguments and the schema coverage is 100%.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states a specific verb ('Start'), a resource ('user sign-in flow'), and a particular method ('device code'). It also mentions the return value ('sign-in instructions'), which distinguishes it from sibling tools like complete_interactive_sign_in or authenticate_mcp_session.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description does not provide any guidance on when to use this tool versus alternatives. It does not mention prerequisites, sequencing, or conditions such as 'use this after authenticate_mcp_session' or 'use complete_interactive_sign_in to finish the flow.' The only implied usage is that it starts a sign-in flow, but no explicit context or exclusions are given.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.